If flowers are the language of love, then Cathy Haibach and Marcus de la fleur speak a dialect that has evolved over thousands of years: the language of the prairie, where their relationship sparked to life.

"With Marcus, I discovered nature in Chicago," says Cathy, now 46 and senior manager of grants at the American Dental Association Foundation. "This whole world just opened. Compass plant, cup plant, prairie dock ... all of a sudden it was like meeting a whole new group of friends. And to do it with someone you have a growing friendship and love with ... it was a really intense experience."

In July 2002, Cathy answered Marcus' personal ad. After exchanging email messages and phone calls, they met for drinks. When Marcus proposed a second date at the Gensburg-Markham Prairie Nature Preserve in south suburban Markham, Cathy jumped at the chance.

"I grew up reading 'Little House on the Prairie,' " says Cathy, who was born in Delaware, studied at the University of Texas at San Antonio and lived in Albuquerque, N.M., for five years. "But when I moved to Chicago (in 1996), it never dawned on me that there were prairies, actual natural habitats."

As Marcus pointed out blazing star, wild bergamot and obedient plant, Cathy began to fall in love with the prairie. And Marcus.

"We sat in the grass, talking forever," says Marcus, now 44 and owner of de la fleur LLC, a landscape architecture firm. Twelve hours later, they ended the day at a sushi restaurant back in the city.

On later dates, the couple hiked at Nachusa Grasslands along the Rock River near Franklin Grove (south of Rockford), the Indiana Dunes National Lakeshore and Bluff Spring Fen in Elgin, which remains Cathy's favorite place for renewal. "Some people go to the mountain to tune inward and find peace," Cathy says. "Bluff Spring Fen is my mountain."

When Cathy met Marcus, she worked as event director for a bicycle advocacy group and had been cultivating a low-impact lifestyle — commuting by bike and train, shopping at thrift stores and cooking from scratch. She was fascinated that Marcus' "work was his play ... he loved his job ... and studied (horticulture) for fun."

For his part, Marcus deeply admired Cathy's open nature and attitude toward life. "Since meeting her, I like to think I'm not that reserved anymore," says Marcus, who grew up in Germany. After working in Germany, Switzerland and England for 10 years, he studied at the prestigious Royal Botanic Gardens, Kew, in London and the University of Sheffield before moving to the Chicago area in 2000 on a contract with The Morton Arboretum. In pursuing his career so determinedly, Marcus had never married. Cathy had had a six-year live-in relationship that fizzled out.

This was different for each of them. As the seasons passed, their love grew. By summer 2004, on a trip to Alaska to visit Cathy's sisters, Marcus proposed.

"I knew they were very dear to her, and I wanted to propose in their presence," Marcus says. He tied the ring to the stem of a daisy picked from her sister's yard. Cathy cried when Marcus got down on bended knee to present the flower, which has since been pressed and framed.

On June 25, 2005, they wed at the prairie at the College of DuPage. The bride carried a bouquet the groom picked from their backyard. "It was so important to get married in a prairie. It was the foundation of our relationship," Cathy says.

Guests endured 96-degree heat on the sunny prairie to watch the lovers exchange vows. Marcus' parents flew in from Germany. Cathy's parents and sister came from Texas.

A few weeks later, on July 16, they married again in a beautiful church wedding in Germany, organized by Marcus' family.

Since returning to the States, Cathy and Marcus have continued living a sustainable lifestyle, inspired by their respect for the ancient soils and important freshwater resources of the Midwest. They transformed the landscape of a rented home in Elmhurst with a green roof, porous pavement, cistern and rain gardens. Encouraged by their successes, they looked for new ways to stretch themselves.

In 2009, they purchased a North Lawndale brick three-flat. Currently they live in the garden apartment with their 7-year-old Rottweiler, Drago, while they renovate the first- and second-floor apartments. Marcus is documenting the project in his blog, "Re-shaping our Footprint" at delafleur.com/blog.

Their commitment to resourceful living is echoed in their relationship.

"We have to remember what's important, whether it's that walk in the prairie, or the minutes we have riding a bike or going to see friends," Cathy says. "Treasure those experiences over the material, and the love over the baggage, the stuff. That's all it is. You can put it aside very easily and still have what's important."

Love lesson: "To make a relationship work, you have to have mutual respect," Marcus de la fleur says. "In times of conflict, getting off that emotional cliff requires a lot of humility, and that is easier with a partner who appreciates and rewards that step."